What Does the Engine Oil Grade Mean?
1 Answers
Automotive engine oil grades represent the viscosity and quality of the oil. Taking "15W-40, 5W-40" as an example: 1. The meaning of the letter "W": "W" stands for Winter. The smaller the number before it, the better the oil's low-temperature fluidity, indicating a lower usable environmental temperature and better protection for the engine during cold starts. For example, 5W represents resistance to external low temperatures of -30°C, while 20W resists low temperatures of -15°C. 2. The meaning of the number after the letter "W": The number after "W" represents the kinematic viscosity of the oil at 100°C. The higher the number, the higher the viscosity. 40 indicates that the kinematic viscosity standard at 100°C is between 12.5mm²/s and 16.3mm²/s.